Compressor-controlling mechanism



July 5 1927; 1,634,542

F. D. HOLDSWORTH COMPRESSOR CONTROLLING MECHANISM 11m I Lg E 7/11 M M in 1.

Patented July 5, 1927.

UNITED STATES PATENT OFFICE.

FRED D. HOLDSWORTH, OF CLAREMON'I, NEW HAMPSHIRE, ASSIGNOR TO SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS.

COMPRESSOR-CONTROLLING MECHANISM.

Application filed December 28, 1922. Serial No. 609,371.

My invention relates to compressor controlling mechanisms, and more particularly to automatic means for controlling the running of a compressor and the loading thereof at appropriate times. I

An object of my invention is to provlde improved compressor controlling mechanism.

Another object of my invention is to provide improved means for controlling the 10; starting and stopping of a compressor 1n accordance with the demands for compressed air and improved means controlled by the starting and stopping of the compressor for controlling the loading and unloading o the compressor. A further object of my 1nvention is to provide improved electro-magnetic control means for the loading and unloading mechanism of a compressor. Other objects and advantages of my invention will hereinafter more fully appear.

In the accompanying drawings I have shown for purposes of illustration one form which my invention may assume in practice.

In these drawings,-

Fig. 1 is a view mainly in elevation, but partially in section, of a compressor system provided with one illustratlve form of my improved controlling means, the electric circnits being shown diagrammatically.

Fig. 2 is an enlarged detail view of a portion of the controlling mechanism, the casing being broken away to facilitate illustration.

Fig. 3 is a central vertical section through the same mechanism with parts shown in elevation.

In the embodiment of my' invention WlllCll I have shown herein for purposes of illustration, I have shown the same incorporated in a compressor system in which a com-' q pressor 1, having a cylinder 2 in whose bore 3 a piston 4 is adapted to be reciprocated by means of a crank shaft 5 and operative connection s, not shown, discharges through a pipe 6 to a receiver 7 any suitable form of discharge valve mechanism 8 being employed. Admission of air to the compressor cylinder takes place past inlet valves 9 which are herein of a familiar lift type, these valves being normally held closed by springs 10 save when opened by reason of the reduction of ressure within the cylinder bore during tlie suction strokes of the piston. For the purpose of opening the inlet valves and maintaining them open and thereby unloading the compressor when desired, Ihave f 21 and 22, and the motor.

provided pistons 11 reciprocable in cylinders 12 to which air may be supplied by way of connections 13 under control of mechanism generally designated 14, hereinafter more fully described, the connections 13 be-y ing connected to the receiver as indicated at 15 through the mechanism 14.

The compressor is driven by a motor diagrammatically shown at M, which motor is provided with starting means having aseries of resistances 16, 17, 18 and 19, all of which are in circuit when the main switch 20 closes the circuit through the-main wires It will be noted that the main switch 20 is controlled by a solenoid 23 which is controlled by a pilot switch 24 whose movements arecontrolled by a diaphragm 25, the diaphragm being responsive directly to receiver pressure by way of a direct connection 26, it being noted that f when the receiver pressure 1s in excess of any predetermined desired amount, the pilot switch 24 will be opened and, when the pressure falls below the desired liinitfthe pilot switch will close andthereby cause the main line switch 20 to be closed. The main line switch has movable therewith a supplemental switch 27 which controls the circuit through a solenoid 28;which serves in turn to close a switch 29 shunting the first resistance 16. The switch 29 carries with it a supplemental switch 30 which closes an operate ing circuit which causes the next succeeding resistance 17 to be shunted, and as eachsuccessive resistance shunting switch closes, it

brings about completion of a circuit through means for closing the next resistance shunting switch. As devices of this type are now uite well known, no further description of the details is believed necessary, save that it may be stated that the movements of each of the resistance shunting switches are controlled by dashpot means which cause the closing movement of the switches to take place relatively slowly, while permitting the opening movements to take place sharply so that arcing is minimized. An examination of the connections illustrated will show that opening of the main lineswitch will cause instantaneous opening of all the resistance shunting switches, and, accordingly, that each time that the motor is stopped it must be brought up to speed again by the gradual cutting out of the starting resistance. It will be observed, moreover, that by reason.

of the presence of the dashpot mechanisms described, a sufiicient timev lapse between the closing of the main circuit and the cutting out of all resistance is provided to permit the motor to come up to running speed.

It will be noted that the last resistance shunting switch carries a supplemental switch 35 which closes a circuit through electro-magnet means constituting a portion of the controlling mechanism 14. This mechanism 14 consists of a combined pneumatic and electric control device in which a ball valve 36 is movable between opposite stationary valve seats 37 and 38 and controls the passage of fluid through the pipe 15 to the cylinders 12. The seat 37 is formed upon a 7 housing member 39 while the seat 38 is carried upon a member 40 which has an upstanding portion 41 providing as at 42 a guide for a stem 43 and providing at 44 a series of vents through which fluid may escape when the valve 36 is in lower position. The plunger 43 has a reduced stem portion 46 which passes through a somewhat larger opening 48 extending through the valve seat 38. At either side of the member 41 is disposed a magnet coil 49, these coils constituting the windings for a magnet 50 of the general horse-shoe type Whose cores are of laminated construction. An armature, which is also laminated as shown at 51, is guided by a series of guide members 52. The armature is traversed by a reduced portion 53 formed on the member 43 at the opposite end thereof from the portion 46 and a spring 54 is located between the armature and the portion 43. TlllS spring is made stiff enough so as to hold the valve 36 closed against full load receiver pressure. For the purpose of adjusting the compression of the spring 54, nuts 55 are arranged upon the threaded portion 56 of the stem 54. Any suitable cover as shown at 57 may be used to protect the mechanism just described, if desired: Secured to the guide members 52 at one side of the magnets is a bar 58 of insulating material extending for substantially the full width of'the magnets. Clip ed on this bar are a series of U- shaped flexible metal clips 61, 62,63 and 64, each having a screw and washer for clamping the clip and to hold one or more connections. The supply wires of the magnets are connected to the clips 61 and 64, respectively. One end of each magnet winding is connected to these same clips. The other ends of the windings are connected to the clips 62 and 63, respectively. The magnets are wound each for a current of 220 v. Hence, by conmeeting the clips 62 and 63 as by a wire 65, the device is adapted for 440 v. current, while by connecting the wires as shown in dotted lines in Fig. 2, i. e. by changing an end of one magnet winding from clip 62 to clip 64, as at 62 and an end of the other magnet winding trom clip 63-450 clip 61, as

at 63, there is suitable arrangement for 220 v. It will be observed that when the magnets 49 are energized by the closing movement of the switch member 35, the armature 51 will be pulled downward and the spring 54 thereby compressed in such man ner as to cause the member 43 to force its portion 46 against the ball valve 36 so as to seat the latter upon the valve seat 37 and so cut ofi the supply of fluid through the pipe 15 and open an exhaust to atmosphere from the cylinders 12 through the port 48 and passages 44, it being understood that the cas ing member 57 is vented to permit the escape of air.

The mode of operation of the illustrative form of my invention will now be readily apparent. Let it be assumed that the parts are in the position shown in Figure 1. It will be evident that the inlet valves are being held open and so that the compressor is unloaded. As receiver pressure drops, due to air consumption for any purpose, the diaphragm 25 will close the pilot switch 24 and thereby cause closing of the main switch 20 and the starting of the motor. The controller mechanism will then gradually cut out the resistance, bringing the motor up to speed and, when the last resistance is cut out, the switch 35 will close the circuits through the magnets 49 and so cause the armature 51 to move the member 43 downward and force the ball 36 to its seat 37 and, since the air will then be free to escape from the cylinders 12, the compressor will be loaded. When the receiver pressure again gets too high, the pilot switch 24 will be opened, re sulting in the opening of all the resistance shunting switches as well as the main line switch and also resulting in the opening ofthe circuit throughthe magnet coils 49 and 7 thereby the air pressure in the line 15 will be enabled to lift the valve 36 from its seat 37 and force it to its seat 38, and this pressure passing to the cylinders 12 will act upon the pistons 11 to unload the compressor. It will be observed that this mechanism is so constructed that, whether the receiver is pumped up or empty, the motor will always start the compressor while the latter is in an unloaded condition.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in other forms withoutdeparting from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a compressor controlling system, a compressor, electric driving means therefor, fluid pressure operated unloading means for said compressor, controller means for said driving means, and means controlled by said controller means for controlling said unloading means including a valve moved in one direction by receiver pressure and means for moving said valve in the opposite direction including a plurality of electro-magnets each ofiset from the line of movement of said valves.

2. In a compressor controlling system, a compressor, electric driving means therefor, fluid pressure operated unloading means for said compressor, controller means for said driving means, and means controlled by said controller means for controlling said unloading means including a valve moved in one direction by receiver pressure and means for moving said valve in the onnosite direction including a plurality of electro-magnets each offset from the line of valve movement and so disposed that the path of valve movement lies wholly between the planes contacting the ends of the magnets.

3. In a compressor controlling system, a compressor, electric driving means therefor, controller means for said driving means, fluid pressure operated unloading means for said compressor comprising a valve casing having oppositely disposed stationary valve seats, a valve intermediate said seats and selectively engageable therewith, and electroresponsive controlling means for said valve operative yieldingly to press said valve to one of its seats and including a transversely disposed armature movable in the same directions as said valve, and means affording a yieldable connection between said armature and valve.

4. In a compressor controlling system, a compressor, electric driving means therefor, controller means for said driving means, fluid pressure operated unloading means for said compressor comprising a valve casing having oppositely disposed valve seats, a valve intermediate said seats, and electroresponsive controlling means for said valve including a plurality of magnets dis osed on opposite sides of the axial line 0 said seats for controlling said unloading means.

v 5. In a compressor controlling system, a compressor, electric drivin means therefor, fluid pressure operated unl dading means for said compressor, controlling means for said driving means, means for controlling said unloading means including a valve casing and a valve disposed therein, controlling means for said valve including a member for actuating said valve and an electro magnet arranged on one side of said member and having an element movable upon energization thereof, and yieldable means disposed between said member and element and always tending to exert a yielding pressure thereon.

6. In a compressor controlling system, a compressor, electric driving means therefor, fluid pressure operated unloading means for said compressor, controller means for said driving means, and means for controlling said unloading means including a valve casing having oppositely disposed valve seats, a valve intermediate said seats, and electro-responsive controlling means for said valve including a plurality of electro-magnets arranged at the opposite sides of the axial line of said seats and an armature movable on energization of said magnets to exert a yielding pressure on said valve to force the same into engagement with one of said seats.

7. In a compressor controlling mechanism, a valve mechanism comprising a casing having a chamber therein freely communicating with a space in which variations in pressure are desired, passages respectively communieating with a source of fluid pressure and with an atmospheric vent, oppositely disposed valve seats formed in said chamber and surrounding said passages, a valve in said casing alternately engageable with said seats, and electro-responsive means including a magnet whose pole pieces extend around said casing for moving said valve toward one of said seats.

8. In a compressor controlling mechanism, a ,valve mechanism comprising a casing having a chamber therein freely communicating with a space in which variations in pressure are desired, passages respectively communicating with a source of fluid pressure and with an atmospheric vent, oppositely disposed valve seats formed in said chamber and surrounding said passages, a valve in saidcasing alternately engageable with said seats, an upwardly projecting guide carried on said casing, a valve engaging member guided in said guide, electro-mag'nets arranged at opposite sides of said ide, an armature actuatcd in one direction by said magnets, and guiding means for said armature supported on said magnets.

9. In a compressor controlling mecha nism, a valve mechanism comprising a casing having a chamber therein freely communicating with a space in which variations in pressure are desired, passages respectively communicating with a source of fluid pressure and with an atmospheric vent, oppositely disposed valve seats formed in said chamher and surrounding said passages, a valve in said casing alternately engageable with said seats, an upwardly projecting guide carried on said casing, a valve engaging member guided in said guide, electro-magnets arranged at opposite sides of said guide, an armature actuated in one direction by said magnets, guiding means for said armature supported on said magnets, and resilient means interposed between said armature and said valve on aging element and operative to move the latter to seat the valve upon said first mentioned seat on energization of said magnets.

10. In a compressor controlling mechanism, a valve, and actuating means therefor comprising a pair of electro-magnets, said valve being disposed between said magnets, a su port of non-conducting material, a series 0 contacts on said support, connections between one of said contacts and one end of one of said magnet windings, connections between another of said contacts and one end of the other of said magnet wind ings, connections between said two last mentioned contacts and the supply wires, c0nnections between the other ends of said magnet windings and others of said contacts, and means interconnecting certain of said contacts to place said windings in series.

11. In a compressor controlling mechanism, a valve, and actuating means therefor comprising a pair of electro-magnets, said valve being disposed between the magnets and between planes contacting the most remote points 1n said magnets, a support of non-conducting material, a series of contacts on said support, connections between one of said contacts and one end of one of said magnet windings, connections between another of said contacts and one end of the other of said magnet windings, connections between said two last mentioned contacts and the supply wires, connections between the other ends of said magnet windings and others of said contacts, and means interconnecting certain of said contacts to place said windings in parallel.

12. In a compressor controlling mechanism, a valve, and actuating means therefor .comprising a pair of electro-magnets, said magnets being arranged with their axes parallel and said valve being disposed between said magnets, a bar of non-conducting material, a series of U-shaped elastic clips on said support, connections between one of said clips and one end of one of said magnet windings, connections between another of said clips and one end of the other of said magnet windings, connections between said two last mentioned clips and the su ply wires, connections between the other en s of said magnet windings and others of said clips, and means interconnecting certain of said clips to place said windings in series.

13. In a compressor controlling mechanism, a valve, and actuating means therefor comprising a pair of electro-magnets said magnets being arranged with their axes parallel and said valve being dis osed between said magnets and between t e planes of the ends thereof, a bar of non-conducting material, a series of U-shaped elastic clips on said support, connections between one of said clips and one end of one of said magnet wlndings, connections between another of said clips and one end of the other of said magnet windings, connections between saidtwo last mentioned clips and the supply wires, connections between the other ends of said magnet windings and others of said clips, and means interconnecting certain of said clips to place said windings in parallel.

In testimony whereof I afiix my signa- 7 ture.

FRED D. HOLDSWORTH. 

